Multiple capacity syringe



March 7, 1967 H. J. KACHERGlS MULTIPLE CAPACITY SYRINGE Filed Jan. 10,1964 United States Patent 3,307,548 MULTIPLE CAPACITY SYRINGE Henry J.Kachergis, Waterbury, Conn, assignor to Scovii] Manufacturing Company,Waterbury, C0nn., a corporation of Connecticut Filed Jan. 10, 1964, Ser.No. 336,910 Claims. (Cl. 128-218) This invention relates to injectionsyringes adapted for use with ampules of different capacities andparticularly with ampules of different lengths. The ampules are usuallyprovided as separate units and preferably, as a cartridge needle unitconsisting of a drug-filled ampule with an attached needle.

The invention presents improvements over the prior art, in manyrespects. One of the purposes of such improvements is to provide for agreater safety and convenience in use. Another very important objectiveis economy of manufacture. Another object is to avoid so far as pos-'sible, holes or crevices which might become contaminated in use.

In pursuing the objective of greater safety and convenience, my improvedsyringe is automatically operable upon threading of the plunger rod tothe piston to a shorter ampule to activate a device for limiting theoutward movement of the plunger rod beyond a predetermined position toinsure against pulling of the piston away from such shorter ampule. Thislimiting device is operative until deliberate motion is applied to theplunger rod, as by twisting it in the opposite direction.

In order to appreciate the pro bems which are solved by this invention,it should be understood that in use, the ampule is secured in thesyringe, the plunger rod applied to the ampule piston, the piston movedto eject air from the needle, and the needle inserted. Then the userwill pull back on the piston to a degree to permit a small amount ofblood to enter the ampule to determine whether or not the needle hasbeen properly inserted. This operation is referred to as aspiration.

When a syringe barrel of sufiicient length to accommodate a longerampule is employed with a shorter ampule, some means must be employed tostop or limit the outward movement of the piston so as to prevent itsbeing withdrawn from the ampule.

The invention is adaptable for use with syringe barrels of theside-entry type which are preferable to the swinging head type shown inthe prior art because they can be manipulated much more quickly and havea better appearance.

Other objects and advantages of the invention will hereinafter morefully appear.

In the accompanying drawing, I have shown for purpose of illustration,one embodiment which the invention may assume in practice. In thedrawing:

FIG. 1 is a small scale side view of an injection syringe for which myinvention is intended;

FIG. 2 is a similar view showing how one of the shorter ampules may beinserted into the barrel of the syringe and also indicating a longerampule in dot-and dash outline;

FIG. 3 is a central vertical section through the head portion of thesyringe, indicating the position of the parts where the plunger rod maybe moved outwardly to its fullest extent;

FIG. 4 is a similar view showing a later stage of such movement;

FIG. 5 is also a similar sectional view showing the parts in position tolimit outward movement of the plunger rod when one of the shorterampules is used;

FIG. 6 is a cross-section on line 6-6 of FIG. 3;

FIG. 7 is a cross-section on line 77 of FIG. 3;

FIG. 8 is an exploded view showing the head and associated parts; and

FIG. 9 is a perspective view of the plunger rod.

The type of ampule which my improved syringe is intended to accommodatehas a vial 10, usually of glass and containing the desired medicine. Itis closed at its outer end by a piston 11 having a threaded stem 12. Atthe outer end, the ampule carries a needle 13 having a collar 14.

The barrel of the syringe, generally indicated by the numeral 15, has awide side opening 16, and to insert the ampule, the needle is placedthrough an opening 17 at the inner end of the barrel, so that the collar14 bears against the inturned end portion of the barrel. The lowerportion of this barrel 15 carries a hook 18 and when the ampule is swunginto the barrel from the posi tion shown in FIG. 2, the hook engagesover the collar 14 to lock the ampule against outward movement relativeto the barrel.

A head 19 is provided, consisting of a top threaded section 19a and abottom plug portion 19b. The head 19 is mounted on the barrel 15 bymeans of its bottom plug portion 19b 'fitting tightly in the outer endof said barrel which is confined against outward expansion by a flangedring 20 which fits tightly around the barrel. The handle element 21rests upon this flanged ring 20 and is held by a screw cap 22 threadedon to the threaded section 19a of the head 19.

The plunger rod 23 has the usual thumb piece 24 at its outer end and acircular boss 25 at its lower end which is internally threaded to fitover the stem 12 of the ampule piston. The plunger rod 23 is guided in abore 26' of the head 19 and also in a hole 27 in the cap 22. The plungerrod 23 has a lengthwise extending groove from near its outer end forapproximately half the length of the rod. T-his groove may be of anydesired shape, but is herein shown as formed by a flattened surface 28so that the groove terminates in a beveled shoulder 29.

The head 19 has a counterbore to provide an annular recess 30 around theplunger rod, and in this recsss is mounted a locking member, preferablyin the form of a ball 31 which is fitted rather snugly in the plungerrod groove or against the flat surface 28. Thus, the ball 31 is freelymovable in said recess 30 in a circular path upon twisting movement ofthe plunger rod in either direction. It will be evident that as long asthe ball 31 is confined against axial movement out of the recess 30, itwill limit the outward movement of the plunger rod beyond apredetermined point, depending upon the inward extent of the groove orthe location of the shoulder 29.

Surrounding the plunger rod is a sleeve 32 whose configuration is bestseen in FIG. 8, and shown in full in 7 FIGS. 3, 4 and 5. It has ashorter portion 33 which is normally located just over the ball 31 toprevent it from coming out of the recess, :and a longer portion 34extends into the recess 30 in the circular path of the ball 31. Whilethis longer portion 34 is indicated as a single axially extending lug,it obviously can be made to take the form of two or more lugs. Thesleeve 32 is confined within the head 19 against axial movement at itsouter end by the cap 22 and at the inner end, by the bottom of therecess 30.

Adjacent one edge of the longer portion 34 is an axially extending slot35, and when the ball 31 is in registry with this slot, it may moveaxially in said slot and over the beveled interior surface 36 of thehead 19 so that the plunger rod is free to move without interferencefrom the locking member or ball 31. The slot 35 is at that side of theshorter sleeve portion 33 to which the ball moves when the plunger rodis twisted in a counterclockwise direction.

3 The position where the ball has escaped from its locking position inthe recess is shown in FIG. 4, where it has moved into a still largercounterbore 37. Now,

when one of the shorter ampules, such as shown in FIG. 7

2, is to be used, the plunger rod 31 must move down and be twistedclockwise to engage it with the threaded stem 12. In this downwardmovement, the groove or flat surface 28 will again move opposite theball 31, and in order to insure that the ball will then move into therecess 30, I have provided a ring, preferably cup-shaped, as indicatedby the numeral 38, together with a spring 3% acting between this ringand the inner surface of cap 22. A lug 40 projects radially inwardlyfrom the ring 38 to engage in the slot of the sleeve 32.

In the twisting action, clockwise of the plunger rod which is essentialto engage it with the piston 11 of a shorter ampule, the ball will movein its circular path and engage that edge of the sleeve longer portion34 opposite the slot 35 (this portion being that shown in FIG. 5); then,the plunger rod may be turned as much as neces sary to tighten it on thestem 12 while the ball merely carries the sleeve 32 and the ring 38around with it. It is thus automatically assured that when the syringeis prepared for use with the shorter ampule, the shorter sleeve portion33 will always be positioned over the ball 31 to retain it in the recess30, and thereby obstruct movement of the piston rod beyond the pointwhere the ball is locked between the shoulder 29 .and the sleeve 32.

After an injection has been made from the shorter ampule, the user willunscrew the plunger rod, Whereupon the ball will move into registry withthe lug on ring 38 which can move upwardly in the slot 35 to allow himto pull the rod all the way to the point where the boss 25 engages thehead.

In the specification and claims, the term inward is used to refer tothat direction toward the needle or distal end of the syringe, and theterm outward refers to the other direction toward the handle orproximate end of the syringe.

What I claim is:

1. A multiple capacity injection syringe adapted to be used with ampulesof different lengths comprising (a) a barrel of sufficient length toreceive a long ampule and having means at its inner end to retain anampule in the barrel;

(b) a head mounted at the outer end of the barrel;

(c) a plunger rod slidably mounted in the barrel head having means atits inner end for attachment to the ampule piston by a relative twistingmovement in one direction; and

(d) means in said head automatically operable in response to suchtwisting movement when said plunger rod is being engaged with the pistonof a shorter ampule to obstruct outward movement of said plunger rodbeyond a predetermined position to insure against pulling of the pistonaway from such shorter ampule.

2. A multiple capacity injection syringe adapted to be used with ampulesof different lengths, comprising (a) a barrel of suflicient length toreceive a long ampule and having means at its inner end to retain anampule in the barrel;

(b) a head mounted at the outer end of the barrel and having an annularrecess;

(c) a plunger rod slidably mounted in the barrel head having means atits inner end for attachment to the ampule piston by a relative twistingmovement in one direction, the upper portion of said plunger rod havinga groove extending lengthwise of the rod;

((1) a locking member normally confined in said recess and groove andmovable in a circular path in said recess by any twisting movement ofsaid plunger rod whereby outward movement of said rod is limited by thelocation of the inner end of said groove; and

(e) means operable by a deliberate movement of said piston rod differentfrom that specified in clause (0) hereof to release said locking memberfrom said annular recess to permit further outward movement of saidplunger rod.

3. A multiple capacity injection syringe adapted to be used with ampulesof different lengths comprising (a) a barrel of sufficient length toreceive a long ampule and having means at its inner end to retain anampule in the barrel;

(b) a head mounted at the outer end of the barrel and having an annularrecess;

(c) a plunger rod slida-bly mounted in the barrel head having means atits inner end for attachment to the ampule piston by a relative twistingmovement in one direction, the upper portion of said plunger rod havinga groove extending lengthwise of the rod;

(d) a ball fitted in said recess and normally engaged in said groove,said ball being movable in a circular path in said recess by anytwisting movement of said plunger rod;

(e) a sleeve surrounding said plunger rod and confined again'stsubstantial axial movement in said head, said sleeve having a shorterportion whose bottom edge engages over the top of said ball to confineit against axial movement out of said recess and a longer portionprojecting into said recess in the circular path of said ball, wherebymovement of said ball in its circular path is free of said sleeve alongthe shorter portion but which carries the sleeve with it when the ballengages the sleeve longer portion; and

(f) a slot in said sleeve along one edge of said longer portion topermit said ball to move axially in said slot and escape from its recesswhen the ball is in registry with the slot.

4. A multiple capacity injection syringe as defined in claim 3 whereinthe inner end of the plunger rod is internally threaded for connectionto the threaded stem of an ampule piston, whereby when said plunger rodis threaded to the piston of a short ampule, said shorter sleeve portionwill move over said ball to confine it in said annular recess.

5. A multiple capacity injection syringe as defined in claim 3 whereinsaid head is provided with a counterbore outwardly of said annularrecess and wherein there are also provided a ring surrounding saidsleeve and mounted in said counterbore for limited movement axiallyrelative to said sleeve, said ring having a radial lug projectinginwardly to engage in said slot in the sleeve and a spring mounted insaid head normally urging said ring in the outward direction.

References Cited by the Examiner UNITED STATES PATENTS ROBERT E. MORGAN,Acting Primary Examiner.

1. A MULTIPLE CAPACITY INJECTION SYRINGE ADAPTED TO BE USED WITH AMPULESOF DIFFERENT LENGTHS COMPRISING (A) A BARREL OF SUFFICIENT LENGTH TORECEIVE A LONG AMPULE AND HAVING MEANS AT ITS INNER END TO RETAIN ANAMPULE IN THE BARREL; (B) A HEAD MOUNTED AT THE OUTER END OF THE BARREL;(C) A PLUNGER ROD SLIDABLY MOUNTED IN THE BARREL HEAD HAVING MEANS ATITS INNER END FOR ATTACHMENT TO THE AMPULE PISTON BY A RELATIVE TWISTINGMOVEMENT IN ONE DIRECTION; AND (D) MEANS IN SAID HEAD AUTOMATICALLYOPERABLE IN RESPONSE TO SUCH TWISTING MOVEMENT WHEN SAID PLUNGER ROD ISBEING ENGAGED WITH THE PISTON OF A SHORTER AMPULE TO OBSTRUCT OUTWARDMOVEMENT OF SAID PLUNGER ROD BEYOND A PREDETERMINED POSITION TO INSUREAGAINST PULLING OF THE PISTON AWAY FROM SUCH SHORTER AMPULE.